Innovating GaN Power HEMTs: The Next Step

Power electronics are all around us. It is one of those technologies we take for granted. When you dive into the world of power electronics you will be surprised by the combination of science and engineering that makes these applications possible. Be it a simple adapter for your smart phone, the server racks in a datacentre or an electric vehicle, power electronics are everywhere and are increasingly important. They control the flow of electricity in many devices we use in our day-to-day life, and one can hardly underestimate the importance of the semiconductor components that lie at the very heart of power electronics. It is estimated that more than 70% of all electrical energy is processed by power electronics before reaching the end user. Imagine the amount of energy saved by improving the efficiency of those devices even if it is by only a few percentage points. Modest improvements can translate into substantial energy savings and CO₂ emission reductions.

It is all about minimizing power losses in the power semiconductor devices. The development of those devices is a challenging endeavour at the very edge of what nature provides us. It requires a sharp engineer’s mind to connect the fundamental material properties to the power device requirements. We are looking for a sharp mind that can help us knock off those percentages in energy savings.

Most power switches are – still today – using silicon as the active semiconductor. Yet wide-bandgap semiconductors such as SiC and GaN offer significant advantages when it comes to energy conversion. Material properties such as higher critical electric fields, higher mobilities in the two-dimensional electron gas, and higher saturation velocities outperform silicon’s properties. Switches made in these wide-bandgap materials can operate at frequencies, voltages and current levels beyond the reach of silicon, enabling more efficient power electronics. Silicon can rely on decades of technological advancements driven by the digital revolution. Applications based on wide-bandgap materials are catching up, yet there are still gains to be made when it comes to efficiency.

The main objective of this PhD topic is to help develop the next generation of advanced GaN devices. The PhD candidate will gain a deep understanding of the device physics and work closely with the GaN teams to develop a new type of lateral high-electron-mobility transistor (HEMTs), particularly a multichannel device. From Technology Computer Aided Design (TCAD) simulations to device characterization, including device design and processing, the PhD student will be involved in all aspects. The focus will be on the study, design, and development of multichannel GaN HEMTs. The PhD student joins a team with over a decade of experience in simulation, processing, and characterization of GaN switches in a top-notch environment. The student will receive training by highly skilled professionals and will be embedded in the GaN device team. Typical tools include Synopsys TCAD software, Python, and semiconductor device characterization equipment for on-wafer electrical measurements.